Electro-optical translator



July 24, 1962 Filed June 10. 1959 F. A. LlTZ ET AL ELECTRO-OPTICALTRANSLATOR 5 Sheets-Sheet 1 IlIllIllIllllllIlIlIlllllIIll/lllIIlIllII/l/L am;

BY MARCEL .1. VOGEL Madan/My.

'ATTORNEY July 24, 1962 F. A. LlTz TAL 3,046,540

ELECTRO-OPTICAL TRANsLA'roR 3 Sheets-Sheet 2 Filed June 10, 1959 July24, 1962 F. A. LlTz ETAT. 3,046,540

, ELECTR0-0PTTCAL TRANsLAToR Filed June 1o, 1959 s sheets-sheet s f'ONDUCTNE y sTR|Rs ,l

RENT coNDuCTTvE TRANSPARENT MATERIAL CONDUCTA/E MA-Tf-RALELECTRoLuMlNEs-NT MATERIAL ELECTRO- LUMiNESCENT- PHOTOCONDUCT IVETRANSLATOR FIG. 5

Y 3,046,540 t -Emscmo-forumcAIJ rnANsLATon FrankA; LitzA and Marcel J.Vogel, SanvJose, Calif., as-

`imsignorssto International-Business Machines Corpora- Ition, New York,NX., a corporation of New York Filed June 10, 1959, Ser; No. 819,401

y10 Claims. (Cl. 340-347) This invention relates in general toelectro-opticalrtranslaters andrelates more particularly to suchtranslators (utilizing lelt'ectroluminescent materials andphotoconductive materials.

v The present invention contemplates a translating device in which'theinfor-mationor data to be translated is convertedto variationsr in -theluminescence Yof discrete elee i. ments of an electroluminescentmaterial, and these lumi-f nescent variations are sensed `byphotoconductive elements through coded openings in `an opaquev codingelement which is disposed between the'electroluminescent `material andthe photoconductive material. The elements of electroluminescentmaterial are preferably in the form of generally parallel stripswhichare selectively excitable under the control of the'in-fformation to bevftranslated. Each off these strips is in registry with the correspondingseries-lof coded openings in the vcoding element, so vthat the outputfrom the coding element is an group of one or more lightl pulses fromthose openings which are'in-registrywith the luminescing strip orstrips. These light 'pulses are the code representation of the'information being translated, and `are projected onto thephotoconductive material.

The photoconductive material is preferably in the formfof generallyparallel strips extending in a direction per# .f pendicular to thedirection of extension'of the electroi` Y luminuescent strips `and inregistry withthe coded openings. Those kphotoconductive strips whichreceive light.I pulses from the coded openings undergo a substantial"resistance change by virtue of'their photoconductive propf- -erties, andthis resistance change is sensed to produce an Aoutput from thetranslator. The structure of the present invention is preferably-'ofunitary 'formv with the -opaquef-f. Ycoding element interposed betweenthe electroluminescentrr material and the'photoconductive material, andthe en-i vftire structurernay lb'edisposed in an opaque enclosure.. 5v5Y :45. ricatedfnin various fOr-ms, Such as. phtogranhic film,

The ytranslator of the'v present invention has a numiberI of vdifferentapplications, such as ay decimahto-binary or :f1

-binarytodecimal converter, Ia read-only memory or a Vprogrammer lforprogramming some type of apparatus in Y'response 'toJ-.aiprogramrepresented -by coded openings ink-Lef the coding element.

Y 4ltis th-ereforean'object of this invention to lprovides an improvedelectro-optical translator.

It is a further object of. the present invention to pro;L vide animproved electro-optical translator utilizing elec -i troluminescentmaterials.

of lan electrolumine'scent material and these variations are y sensed byphotoconductive elements through coded open-,2

.ings inzan opaquecoding element.

. i Other `objects of thel mventionwrllj-be pointed out in- "the-following description and; clairnsrand, illustrated inVffrthexaccompanying `drawings which disclose-by way of .f eXarnple', the,principle of the invention;andthebest'mode' '.Igwhich hasibeencontemplated (if-.applyingv that principle..,

:1, In .the drawings:

FIG. l is an explodedperspectiveviewgillustrating the f f structure ofatranslatorfin ,accordance-with the prese-nt l 70 same ydirection as.thetransparent ,conductive 'strips 26.

f invention;

i `FIG.12y is an elevationalyiew in cross section illustraty 3,046,540Patented July 274,1962

r* rs ice lFIG.c 5 is a perspectivejview off an alternative embodimentof y"the present `invention'for programm-ingapparatus in'response to aprogram represented by'c'oded openings in a moving `coding element.

'Referring to FIG. liby character! reference, there is `shown'inexploded forma translatorll'of generally rectangular form.' Thetranslator includes ya pair-lof plate vmembers 12 and 1310i glassloother .transparent sub- 15' strate material, Ysuch as mic'a,liwhch -formthe body of :the structure *on which the electrominescent and"photoconductive materials are supported. v'Member 12' is prog videdl onone surface with a layer 14 of transparent, electrically conductive'material such as .stannie oxide. A layer 1-5' ofl electroluminescentmaterial, suchsas ZnSCu, is-disposedonttransparent vconductive material14, and electroluminescent material, 15 is 'overlaid with ispaced strips16 of electrically conductive material such as silver or' aluminum. Theelementsjlkl 15 and 16 form the meansr for converting-information intovariations; in the Vlur'riinesce'nce ofthe,electroluminescentmaterial15. Al-

y though-the operation will-beidescribed in more detail below,,itl-willbe clear at'this point ,thatbyqsupplying electrical..currents"to, selected o nespfl the Velectrically conductive strips 16, theportions ofwtheelectrolpmines- Lcent layenlSfnderlying these stripsAwill luminesce and -flthis luminescence willfbe projected throughnthetrans- -parentzconductive layer 14 andthe transparent member 1.2. i iopaqueycoding elementy v21 is ,disposed between plates 12 and -13 andisprovidedwith a plurality kor coded `:openings 2 21tfor selectivelypassing-light produced by the Lluminescence of material 15- g throughplate 13 to the photocondnctive elements. The loca-tions of coded open-Aings 22,1nfthe0naque' member 21 ,WilldPHF P011 the particulancode beingused ini-theV conversion, land it lwill `4`beunderstoodthatjthepositions-of these yopenings may 1 It; is also understood-thaty thiscode-element. may :be 'fabpunched cards, hard' enameled transparentplastic forms f and the ,lilrefand may .Ibe fxed, movable orreplaceable. kItiisjalsonunderstoodv-that,'the code element may be ation., lPlate 13is.,backed by-=a plurality yof strips 26 of a suitablephotoconductive material such as cadmium selenide-orvcadmiumsulfide.Member 13 ispprovided on 5,5v-of-,conductive Vstrip electrodes,;26a,through 26m, which g extend acio'ss member 13 inaudirection'perpendicular to the directionofpthe conductive stripsl.Conductive i method, such; las, by evaporation ,of platinum, jzinc or6()` silver, or;` preferably/.by .forming separate tra,r'isparent SnOz'strips on the member 13'to providevthe electrical insulatingvspaces,..7a,through27lcl1etveen these strips as l shown. Transparentconductivestrips26areybest,formed byrirst depositinga layer oftiarisparent'cbnductive mate- 65.,.rial. on the entire suraceof imemberA13"and` n sandblasting.oracidA etch-ing.111,51?llllel4 grooves tofprmthe insulating gaps Z7.r t V l .i

Conductive strips 2.61am overlaid'bystripslzahrough 28h. of.photocfonduct'ive'rnaterial which, extendX in the Asishown in FIG. 2forthis embodiment, each o fphotoconductive strips 28l-vismpositionedpsoasto, span'one of .fbevariedin accordanevwith the particular codeutilized?V matrix offferroelectricvlight.gatessuch as lbariunntitanate50 zto permit electronicjcontrol of the code element'conguraits surfaceopposite to .coding element 21 with appluralityA s'trips26 may be formedon :member 13 by anysuitable spaanse i tor strip.

All of the elements of the translator may be disposed closely adjacenteach other as illustrated in FIG. 2, and the entire assembly may ybeenclosed in a suitable opaque enclosure 30. Enclosure 30` may be, `forexample, an opaque plastic material in which the translator assembly isencapsulated after assembly of the components.

The electrical connections to the diiterent elements of the translatorare best illustrated in FIG. 3, which is a perspective view, partly insection7 of the device of FIGS. 1 and 2, utilized as a decimal to binaryconverter. In FIG. 3, opaque enclosure 30 has been removed -for purposesof clarity, but it will be understood that in practice this enclosurewould be provided to shield the device from ambient light. In theembodiment of FIG. 3 it is assumed that a decimal digit is to beconverted to binary form utilizing a well known binary code employingthe Y' code elements l, 2, 4, 8 and n2, The decimal digit to fbeconverted is entered into the system by means shown schematically asswitches 400 through 4tlg. Switches 40o-4tlg may be mechanical switcheswhich are selectively closed to represent the particular decimal digitassociated therewith, or these switches may be photocon* ductors or anyother type of switching elements capable of being selectively energizedin response to the desired decimal digit.

One terminal of each of the switches is connected to an associated oneof the conductive strips 16 which are numbered 160 through 169 to showtheir association with the different digits. The other terminals of theswitches are connected in common to one terminal of a current source 32.The other terminal of source 32 is connected to the transparentconductive layer 14 which underlies electroluminescent layer 15 and theconductive strips 16. It will be seen that when one of switches 40o-409is closed, current will flow from source 32 through this closed switchto the associated one of the conductive strips 16, then through theVportion of the electroluminescent Inaterial 15 which is directly underthis conductive strip to the transparent conductive layer 14 and back tothe other terminal of source 32. The electroluminescent material "15thus has current flow therethrough in the portion thereof directlyunderlying the conductive strip 16 through which current is flowing.Material 15 will thus luminesce only in the area immediately underlyingthe energized one of conductive strips 16, to produce a strip 0fluminescence corresponding to the configuration of the energizedconductive strip 16. Y

Assume that switch 405 has been closed, representing the decimal digit5, thus producing current flow through the conductive strip` 165 andproducing a strip of electroluminescence in the portion ofelectroluminescent layer 15 immediately underlying conductive strip 165.This electroluminescence is projected through transparent conductivemember 14 and member 12 to the column of coded openings 22 representingthe digit 5 in the coding element 21.

The disposition of the openings 22 in the 5 column ofcoding element 2'1will depend upon the particular code being utilized, but regardless ofwhat code is employed, the light from the luminescing strip will beprojected through these openings to produce one or more .discrete-lightpulses representing the code for that par- Vticular digit. These codedlight pulses pass through member 13 and transparent conductive material26 to V`selectively fall upon the photoconductive strip or strips Asshown in FIG. 3, the photoconductive strips 26 are connection with theabove embodiment.

by the B+ terminal 51. This may be an A C. or `D.C. source and has noelectrical coupling to the electroluminescent power source. Current fromterminal 51 is supplied through four parallel paths 51h, 51e, 51h, 51kto the ends of four common photoconductor electrode strips 26h, 26e,2611 26k. The 'other ends of the other eight conductive electrode strips26a, 26C, 26d, 26f, 26g, 26 26j, 26m are connected to a series ofexternal circuit con-yY ductors 52a, 52C, 52d, 52,4?, 52g, 52 52j, 52m.Each of conductors 52 is thus connected to a transparent conductivestrip 26 at a point which is separatedfrom any point of input connection51 by one of the insulating gaps 27. Thus, current can ow betweenconductors 51 and conductors 52 only through one of the photoconductivestrips 2S. Current from each of conductors 52 goes through an associatedload which is shown in this embodiment 4as resistors 53a, 53C, 53d, 53f,53g, 531, 53j, 53m. This load :however could be an electroluminescentelement, a transistor, a neon lamp or the grid of a vacuum tube. Theother terminals of yresistors 53 are connected in common to a return forthe B+ source 51. Resistors 53 represent one form of output deviceacross which the binary coded output signals appear for subsequentutilization.

In the absence of lightpulses on the photoconductive strips, the fullsupply voltage appears across each of the photoconductor strips owing totheir extremely high, dark impedance. When a photoconductor strip isilluminated, its impedance decreases and a voltage VL appears across theload according tothe Kformula signicant change in the resistance of thephotoconductive strip to produce a large. voltage swing across theassociated load resistor 53. sensed by the utilization apparatus such asneon indicator lamps or electroluminescent elements (not shown), toprovide an indication of the binary representation of the particulardecimal digit being converted. It is understood that the load may be theinput to other optoelectronic devices.

FIG. 4 illustrates an alternative embodiment of the present invention inwhich the translator has a cylindrical shape. The device of FIG. 4contains the same elements shown in the embodiment of FIGS. 1, 2 and 3,`and these elements function inthe same manner described in The deviceof FIG. 4 includes a plurality of strips 66 of a conductive materialwhich are similar in function to the strips 16 in the above embodiment.The strips 66 are spaced apart from each other around the periphery of acylinder and` each of the strips extends longitudinally of the axis ofthe cylinder. A layer of electroluminescent material is disposed underthe conductive strips 66 and corresponds to the electroluminescent layer15. Electroluminescent layer 65 is underlaid by a transparent conductive-layer`64 which rests on a transparent vglass or mica base 62.

The photoconductive portion of the apparatus ofV FIG.

4 includes a plurality of strips of photoconductive Vmaterial 78disposed `around the inner'surface of the cylinder and extending in adirection perpendicular to. the di- These voltage swings are rection ofextension of the conductive strips 66. Photoconductive strips 73 spaninsulating gaps between adjacent strips of a transparent conductivematerial 76 which in turn rests on a transparent glass or mica member73. The insulating gaps. are similar to gaps 27 of FGS. l, 2 and 3 'andserve toprovide electrical insulation between adjacent strips ofmaterial 7 6.

The space between cylindrical members 62 and 73 is occupied by 4acylindrical opaque coding element 71 which is similar in function to thecoding element 21 ofthe abovedescribed embodiment. Coding element 71 ispreferably freely insertable in and removable from the space betweenmembers 62 and 73 so as to facilitate the use of different codingelements 71 in the programmer.. Codn ing element 71 is provided with aplurality of coded openings' 72 which serve to encode the light producedby luminescent material 65 into light pulses for trans fission to thephotocon'ductive strips 78. It will be understood that in practice thedevice will be enclosed in an opaque enclosure to provide shielding fromambient light.

When suitable electrical connections (not shown) are made to the deviceof FIG. 4 in a manner similarl to that shown in FIG. 3, the device maybe utilized as adecimall'to-binary or binary-to-decimal converter as inthe embodiment of FIGS. l, 2 and 3. Alternately, the device may serve asa read only memory with vthe memory stored in the openings 72 in codingelement 71 and read out therefrom whenV the associated electricalcircuits are energized or addressed. It will be understood thatdifferent coding elements 71 may be utilized to vary the memory storedin the device.

FIG. 5 illustrates an additional embodiment of the present inventionutilized as a programming device. The translating device 11 of FIG. 5 issimilar to'that shown in FlGS. 1, 2. and 3, except that the codingelement in the embodiment of FIG. 5 is "in `the form of a movable member81 which is movable through the space between members 12 and 13. Codingelement 81 contains, ajplurality of separate programs, such as program Cshown, each program comprising a plurality of coded openings which arein registry with the electroluminescent and photoconductive members whenthe program is positioned p in device 11. Coding element 81 may beadvanced in steps -by suitable means (not shown), with each separatestep presenting a different program to the translator.

6 tor strips correspond to specific register and control gates. To add Aand B and store the results in C, the code mask in step l'would containa code instruction to reset the accumulator C through a translatoroutput photoconductor control gate; next, commutating to EL strip 2would scan the data stored in the'code mask which would transfer thecontents of A register to C register; stepping to EL strip 3 wouldresult in the transfer of the contents of registerB to register (3, thusgiving the results A and B in C as required. Step 4 might containcontrol instructions to transfer the contents Wit-h the appropriateelectrical connections to the translator input electroluminescentstrips, the output from the photoconductive strips may be utilized tocontrol or program Vsome equipment as a function of the differentprograms represented by the different openings in element 81.

As an example, format control of a printer coupled to `an accountingmachine may be effected 'by commutating through the electroluminescentstrips which in this case would'correspond to different specific linepositions on a given form. The coded mask would contain the informationcorresponding to the addresses of data stored in the accounting machineregisters to be printed in specific fields or columns on the form.Accordingly, the translator photoconductor outputswould gate specificdata registers and also operate on the printer horizontal and verticaltab controls to effect the printing of specificpdata, such las quantityor unit price, in appropriate fields or columns on the form. Changingforms would require a change in code mask. This is analogous to changingplug boards or plug board Wiring on some typical present accountingmachines, and represent a major improvement over this technique. K

From this it becomes apparent that other plug board functions may beperformed using this typical solid state translator technique. Otherexamples are computer subroutine programming or stored program computerplug board functions.

Computer subroutine programming may be illustrated by the followingexample: Let each electroluminescent strip correspond to a program stepand the photoconducof' register C to an output printer, etc.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to the preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of thedeviceillus'trated and in itsV operation may be made by those skilled inthe art, without departing from the spirit of the invention. It is theintention, therefore, to be limited only as indicated by the scope ofthe following claims.

'What is claimed is:

l. An electro-optical translator for converting a frstsignal to anothersignal in accordance with a' given conversion code comprising 'anelectroluminescent member, a plurality of strip members overlying saidmember for producing electrofluminescence of selected strips of saidelectroluminescent member as a function of said first signal, an opaquecoding element having openings therein corresponding to said conversioncode disposed adjacent said electroluminescent member for modulatingsaid selected electroluminescence in Vaccordance with said conversioncode between said first signal and said second signal, and aphotoconductive material having different areas thereof responsive tosaid modulated electroluminescence for producing an output signalrepresenting said second signal.

2,. An electro-optical translator for converting a first signal ltoanother signal in accordance with a given conversion code comprising anelectroluminescent member, a plurality of electrically conductive stripmembers overlying said member, means for selectively energizing saidstrips as a function of said first signal to produceelectrol-uminescence of selected strips of said electroluminescentmember, an opaque coding element having openingsw therein correspondingto said conversion code disposed adjacent said electroluminescent memberfor modulating said selected electroluminescence in accordance with saidconversion code between said first signal and said second signal, and aphotoconductive material having different areas thereof responsive tosaid modulated electroluminescence for producing an output signalrepresen-ting said second signal.

3. An electro-optical translator for converting a rst signal `to anothersignal in accordance with a given conversion code comprising anelectroluminescent member, a plurality'of generally parallelelectrically conductive strips overly-ing said member, means forselectively' energizing said strips as a function of 'saidrst signal toproduce electroluminescence of selectedlportions of saidyelectroluminescent member, yan opaquecoding element having openingstherein corresponding to said conversion code disposed adjacent saidelectroluminescentv member for modulating said selectedelectroluminescence in accordance with said conversion code between said4first signal and said second signal, and a plurality of parallel strips:of photoconductive material extending normal to said conductive stripsand responsive to said modulated electroluminescence for producing anoutput signal representing said second signal.

4. An electro-optical translator for converting a first signal toanother signal in accordance Awith a given conversion code comprising acylindrical electroluminescent member, a plurality of electricallyconductivemembers overlying said member, means for selectivelyenergizing said strips as a function of said first signal to produce.

electroluminescence of selected strips of said electroluminescentmember, an opaque coding element disposed adjacent said member andhaving openings for modulating said selected electroluminescence inaccordance With said conversion code between said first signal and saidsecond signal, and a plurality of strips of photoconductive materialdisposed adjacent said openings and responsive to, said modulatedelectroluminescence for producing an output signal'representing saidsecond signal.

5. An electro-optical translator for converting a first signal to asecond signal in accordance with a given code comprising anelectroluminescent member, means for producing electroluminescence ofselected areas of said electroluminescent member in response to saidfirst signal, an opaque coding element disposed adjacentsaid'electroluminescent member and having coded openings therein inregistry With different areas of said electroluminescent material fortransmitting light from said electroluminescent material in accordancewith said code, a photoconductive material disposed on the opposite sideof said coding element from said eleetroluminescent material and havinga plurality of separate photoconductive elements in registry with saidopenings for receiving said transmitted light, and means responsive tochanges in the electrical characteristics of said photoconductiveelements as a result of receipt of said transmitted light for producing`an indication of said second signal. l

6. An `eleetro-ptical translator for converting a first signal toanother signal in accordance with a given code comprising a cylindricalelectroluminescent member, means for producing electroluminescence ofselected areas of said electroluminescent member in response to saidfirst signal, a cylindrical opaque coding element disposed adjacent saidelectroluminescent member and having coded openings therein in registryWith different areas of said electroluminescent member for transmittinglight from said electroluminescent member in accordance with said code,a cylindrical photoconductive member disposed on vthe opposite side ofsaid coding element from said electroluminescent member and having aplurality of separate photoconductive elements in registry with saidopenings for receiving said transmitted light, and means responsive ktochanges in the electrical characteristics of said photo- .conductiveelements as a result of receipt of said transinitted light for producingan indication of said second signal.

7. An electro-optical translator for converting a irst signal to anothersignal in accordance wtih a given code program for programming an outputdevice comprising an electroluminescent member, means for producingelectroluminescence ofselected areas to said electroluminescent memberin response to said lirst signal, a movable coding element having aplurality of different programs thereon which are separately disposableadjacent said electroluminescent member, `each of said programs com-.prising a plurality of coded openings which are in registry terialdisposed `on the opposite side of said coding ele-l ment from saidelectrolumineseent member and having a `plurality of separatephotoconductive elements in registry With said openings for receivingsaid vtransrnittedlight, and means responsive to changes in theelectrical characteristics of said photoconductive elements as a resultof receipt of said transmitted light for producing an output signal.

8. An electro-optical translator for converting-a rst signal to anothersignal in accordance with `a given code comprising an electroluminescentmember, a plurality of 'i parallel electrically conductive stripsoverlying said member, means for selectively energizing said strips as afunction of said first signal to produce electroluminescence of selectedareas of said electroluminescent member underlying said strips, a codingelement disposed adjacent said electroluminescent member and havingcoded openings therein in registry with -diierent areas of saidelectroluminescent member for transmitting light from saidelectroluminescent member in accordance with said code, a plurality ofstrips of photoconductive material disposed on the opposite side of saidcoding element from said elec# troluminesccnt material and extending ina direction normal to said conductive strips, each of saidphotoconductive strips being in registry lwith some of said openings forreceiving said transmitted light, and means responsive to changes in theelectrical characteristics of said photoconductive elements as a resultof receipt of said transmitted light for producing an indication of saidsecond signal.

9. An electrooptical*translator for sequentially carrying out theinstructions of a programcomprising an electroluminescent member, aplurality of generally parallel electrically conductive strips overlyingsaid member and corresponding to the steps of said program, means forselectively energizing said strips as a function of said program toproduce electroluminescence of selected portions of saidelectroluminescent member, an opaque coding element having openingstherein corresponding to said program disposed adjacent saidelectroluminescent memberfoij modulating said selectedelectroluminescence in accordance With said program instructions, and apluralit'y of parallel strips of photoconductive material eX- tendingnormal to said conductive strips and responsive to vsaid modulatedelectroluminescence for producing an output signal in accordance Withsaid program.

10.?An electro-optical translator for converting a tirst signal toanother signal in accordance With a given con# Version code comprisingan electrolurninescent member, a plurality of strip members overlyingsaid Vmember for producing electroluminescence of selected strips ofsaidelectroluminescent member -as a function of said first signal, aplurality of terroelectric light gates for controllably modulating saidselected electroluminescence in accordance with said conversion codebetween said first signal yand said second signal, and `aphotoconductive material having different areas thereof responsive tosaid modulated electroluminescence for producing an output signalrepresenting said second signal.

References Cited in the tile of this patent UNITED STATES PATENTSY JayApr. 12, 1960

